1 /* 2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "code/vtableStubs.hpp" 27 #include "compiler/compileBroker.hpp" 28 #include "compiler/disassembler.hpp" 29 #include "memory/allocation.inline.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "oops/instanceKlass.hpp" 32 #include "oops/klassVtable.hpp" 33 #include "oops/oop.inline.hpp" 34 #include "prims/forte.hpp" 35 #include "prims/jvmtiExport.hpp" 36 #include "runtime/handles.inline.hpp" 37 #include "runtime/mutexLocker.hpp" 38 #include "runtime/sharedRuntime.hpp" 39 #include "utilities/align.hpp" 40 #ifdef COMPILER2 41 #include "opto/matcher.hpp" 42 #endif 43 44 // ----------------------------------------------------------------------------------------- 45 // Implementation of VtableStub 46 47 address VtableStub::_chunk = NULL; 48 address VtableStub::_chunk_end = NULL; 49 VMReg VtableStub::_receiver_location = VMRegImpl::Bad(); 50 51 52 void* VtableStub::operator new(size_t size, int code_size) throw() { 53 assert(size == sizeof(VtableStub), "mismatched size"); 54 // compute real VtableStub size (rounded to nearest word) 55 const int real_size = align_up(code_size + (int)sizeof(VtableStub), wordSize); 56 // malloc them in chunks to minimize header overhead 57 const int chunk_factor = 32; 58 if (_chunk == NULL || _chunk + real_size > _chunk_end) { 59 const int bytes = chunk_factor * real_size + pd_code_alignment(); 60 61 // There is a dependency on the name of the blob in src/share/vm/prims/jvmtiCodeBlobEvents.cpp 62 // If changing the name, update the other file accordingly. 63 BufferBlob* blob = BufferBlob::create("vtable chunks", bytes); 64 if (blob == NULL) { 65 return NULL; 66 } 67 _chunk = blob->content_begin(); 68 _chunk_end = _chunk + bytes; 69 Forte::register_stub("vtable stub", _chunk, _chunk_end); 70 align_chunk(); 71 } 72 assert(_chunk + real_size <= _chunk_end, "bad allocation"); 73 void* res = _chunk; 74 _chunk += real_size; 75 align_chunk(); 76 return res; 77 } 78 79 80 void VtableStub::print_on(outputStream* st) const { 81 st->print("vtable stub (index = %d, receiver_location = " INTX_FORMAT ", code = [" INTPTR_FORMAT ", " INTPTR_FORMAT "[)", 82 index(), p2i(receiver_location()), p2i(code_begin()), p2i(code_end())); 83 } 84 85 86 // ----------------------------------------------------------------------------------------- 87 // Implementation of VtableStubs 88 // 89 // For each hash value there's a linked list of vtable stubs (with that 90 // hash value). Each list is anchored in a little hash _table, indexed 91 // by that hash value. 92 93 VtableStub* VtableStubs::_table[VtableStubs::N]; 94 int VtableStubs::_number_of_vtable_stubs = 0; 95 96 97 void VtableStubs::initialize() { 98 VtableStub::_receiver_location = SharedRuntime::name_for_receiver(); 99 { 100 MutexLocker ml(VtableStubs_lock); 101 assert(_number_of_vtable_stubs == 0, "potential performance bug: VtableStubs initialized more than once"); 102 assert(is_power_of_2(N), "N must be a power of 2"); 103 for (int i = 0; i < N; i++) { 104 _table[i] = NULL; 105 } 106 } 107 } 108 109 110 address VtableStubs::find_stub(bool is_vtable_stub, int vtable_index) { 111 assert(vtable_index >= 0, "must be positive"); 112 113 VtableStub* s = ShareVtableStubs ? lookup(is_vtable_stub, vtable_index) : NULL; 114 if (s == NULL) { 115 if (is_vtable_stub) { 116 s = create_vtable_stub(vtable_index); 117 } else { 118 s = create_itable_stub(vtable_index); 119 } 120 121 // Creation of vtable or itable can fail if there is not enough free space in the code cache. 122 if (s == NULL) { 123 return NULL; 124 } 125 126 enter(is_vtable_stub, vtable_index, s); 127 if (PrintAdapterHandlers) { 128 tty->print_cr("Decoding VtableStub %s[%d]@" INTX_FORMAT, 129 is_vtable_stub? "vtbl": "itbl", vtable_index, p2i(VtableStub::receiver_location())); 130 Disassembler::decode(s->code_begin(), s->code_end()); 131 } 132 // Notify JVMTI about this stub. The event will be recorded by the enclosing 133 // JvmtiDynamicCodeEventCollector and posted when this thread has released 134 // all locks. 135 if (JvmtiExport::should_post_dynamic_code_generated()) { 136 JvmtiExport::post_dynamic_code_generated_while_holding_locks(is_vtable_stub? "vtable stub": "itable stub", 137 s->code_begin(), s->code_end()); 138 } 139 } 140 return s->entry_point(); 141 } 142 143 144 inline uint VtableStubs::hash(bool is_vtable_stub, int vtable_index){ 145 // Assumption: receiver_location < 4 in most cases. 146 int hash = ((vtable_index << 2) ^ VtableStub::receiver_location()->value()) + vtable_index; 147 return (is_vtable_stub ? ~hash : hash) & mask; 148 } 149 150 151 VtableStub* VtableStubs::lookup(bool is_vtable_stub, int vtable_index) { 152 MutexLocker ml(VtableStubs_lock); 153 unsigned hash = VtableStubs::hash(is_vtable_stub, vtable_index); 154 VtableStub* s = _table[hash]; 155 while( s && !s->matches(is_vtable_stub, vtable_index)) s = s->next(); 156 return s; 157 } 158 159 160 void VtableStubs::enter(bool is_vtable_stub, int vtable_index, VtableStub* s) { 161 MutexLocker ml(VtableStubs_lock); 162 assert(s->matches(is_vtable_stub, vtable_index), "bad vtable stub"); 163 unsigned int h = VtableStubs::hash(is_vtable_stub, vtable_index); 164 // enter s at the beginning of the corresponding list 165 s->set_next(_table[h]); 166 _table[h] = s; 167 _number_of_vtable_stubs++; 168 } 169 170 171 bool VtableStubs::is_entry_point(address pc) { 172 MutexLocker ml(VtableStubs_lock); 173 VtableStub* stub = (VtableStub*)(pc - VtableStub::entry_offset()); 174 uint hash = VtableStubs::hash(stub->is_vtable_stub(), stub->index()); 175 VtableStub* s; 176 for (s = _table[hash]; s != NULL && s != stub; s = s->next()) {} 177 return s == stub; 178 } 179 180 181 bool VtableStubs::contains(address pc) { 182 // simple solution for now - we may want to use 183 // a faster way if this function is called often 184 return stub_containing(pc) != NULL; 185 } 186 187 188 VtableStub* VtableStubs::stub_containing(address pc) { 189 // Note: No locking needed since any change to the data structure 190 // happens with an atomic store into it (we don't care about 191 // consistency with the _number_of_vtable_stubs counter). 192 for (int i = 0; i < N; i++) { 193 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) { 194 if (s->contains(pc)) return s; 195 } 196 } 197 return NULL; 198 } 199 200 void vtableStubs_init() { 201 VtableStubs::initialize(); 202 } 203 204 void VtableStubs::vtable_stub_do(void f(VtableStub*)) { 205 for (int i = 0; i < N; i++) { 206 for (VtableStub* s = _table[i]; s != NULL; s = s->next()) { 207 f(s); 208 } 209 } 210 } 211 212 213 //----------------------------------------------------------------------------------------------------- 214 // Non-product code 215 #ifndef PRODUCT 216 217 extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index) { 218 ResourceMark rm; 219 HandleMark hm; 220 Klass* klass = receiver->klass(); 221 InstanceKlass* ik = InstanceKlass::cast(klass); 222 klassVtable vt = ik->vtable(); 223 ik->print(); 224 fatal("bad compiled vtable dispatch: receiver " INTPTR_FORMAT ", " 225 "index %d (vtable length %d)", 226 p2i(receiver), index, vt.length()); 227 } 228 229 #endif // PRODUCT